mcp-nodejs-debugger

# MCP Node.js Debugger An MCP server that gives Cursor or Claude Code access to Node.js at runtime to help you debug: [`@hyperdrive-eng/mcp-nodejs-debugger`](https://www.npmjs.com/package/@hyperdrive-eng/mcp-nodejs-debugger). ## Demo ### Cursor https://github.com/user-attachments/assets/c193a17e-b0e6-4c51-82aa-7f3f0de17e1a ### Claude Code https://github.com/user-attachments/assets/adb7321b-3a6a-459b-a5c9-df365710d4d8 ## Quick start ### Cursor 1. Add to Cursor (`~/.cursor/mcp.json`)  ```diff + { + "mcpServers": { + "nodejs-debugger": { + "command": "npx", + "args": ["@hyperdrive-eng/mcp-nodejs-debugger"] + } + } + } ``` 1. Run a Node.js server in [debug mode](https://nodejs.org/en/learn/getting-started/debugging) (i.e. with the `--inspect` flat) ```sh node --inspect {file.js} ``` 1. Ask Cursor to debug your Node.js server at runtime  ### Claude Code 1. Add to Claude Code ```sh claude mcp add nodejs-debugger npx @hyperdrive-eng/mcp-nodejs-debugger ``` 1. Start Claude Code ```sh claude ╭───────────────────────────────────────────────────────╮ │ ✻ Welcome to Claude Code research preview! │ │ │ │ /help for help │ │ │ │ Found 1 MCP server (use /mcp for status) │ ╰───────────────────────────────────────────────────────╯ ``` 2. Run a Node.js server in [debug mode](https://nodejs.org/en/learn/getting-started/debugging) (i.e. with the `--inspect` flat) ```sh # In another terminal node --inspect {file.js} ``` 3. Ask Claude Code to debug your Node.js server at runtime ```sh > I'm getting a runtime error in Node.js {YOUR_RUNTIME_ERROR} Please help me debug this error at runtime using the nodejs-debugger mcp. ``` ## Usage ### Claude Code 1. Add to Claude Code ```sh claude mcp add nodejs-debugger npx mcp-nodejs-debugger ``` 1. Verify connection ```sh > /mcp ⎿ MCP Server Status • nodejs-debugger: connected ``` 1. Remove from Claude Code ```sh claude remove nodejs-debugger ``` ### Cursor 1. Add to Cursor (`~/.cursor/mcp.json`) ```diff + { + "mcpServers": { + "nodejs-debugger": { + "command": "npx", + "args": ["@hyperdrive-eng/mcp-nodejs-debugger"] + } + } + } ``` 1. Verify connection:  1. Remove from Cursor (`~/.cursor/mcp.json`): ```diff - { - "mcpServers": { - "nodejs-debugger": { - "command": "npx", - "args": ["@hyperdrive-eng/mcp-nodejs-debugger"] - } - } - } ``` ## Example ### Cursor 1. Run this simple Node.js app: [github.com/mdn/express-locallibrary-tutorial](https://github.com/mdn/express-locallibrary-tutorial): ```sh node --inspect ./bin/www ``` 1. Ask Cursor to set a breakpoint   2. Create a book at [`localhost:3000/catalog/book/create`](http://localhost:3000/catalog/book/create)  1. Watch Cursor capture runtime state  ### Claude Code 1. Here is a buggy Node.js server: ``` node --inspect index.js Debugger listening on ws://127.0.0.1:9229/2862f5a2-8618-4516-8429-1248b397e9b4 ####################### ## THE RUNTIME ERROR ## ####################### MongooseServerSelectionError: Could not connect to any servers in your MongoDB Atlas cluster. One common reason is that you're trying to access the database from an IP that isn't whitelisted. Make sure your current IP address is on your Atlas cluster's IP whitelist: https://www.mongodb.com/docs/atlas/security-whitelist/ at _handleConnectionErrors (/Users/arthur/Documents/thirdparties/mdn/express-locallibrary-tutorial/node_modules/mongoose/lib/connection.js:1110:11) at NativeConnection.openUri (/Users/arthur/Documents/thirdparties/mdn/express-locallibrary-tutorial/node_modules/mongoose/lib/connection.js:1041:11) at async main (/Users/arthur/Documents/thirdparties/mdn/express-locallibrary-tutorial/app.js:35:3) { reason: TopologyDescription { type: 'ReplicaSetNoPrimary', ser